I. Purpose The Mayo Clinic Cancer Center (MCCC) oversees patient safety and data monitoring through its Data and Safety Monitoring System (DSMS). The DSMS contains several elements including the Cancer Center Clinical Research Administrative Subcommittee (CCCRAS) and the Cancer Center Clinical Studies Oversight Committee (CCCSOC). The function of each of these committees is described below as it pertains to the DSMS. The committees are integrated between the three Mayo campuses and function in a collaborative manner to monitor patient safety and data quality. Each committee has authority to halt ongoing clinical research if concerns relating to patient safety are identified. Patient safety is further enhanced through inclusion of required components to procedural sections of MCCC sponsored clinical trials, including early stopping rules. The operations and procedures of these committees are evaluated each year as part of the annual review of the Data and Safety Monitoring Plan (DSMP).